Apparatus and method for making fluid filled units

ABSTRACT

The present invention concerns a machine and a method for converting a web of preformed pouches to dunnage units. In one exemplary embodiment the machine includes a drive, a blower, and a sealing mechanism. The drive is arranged to move the web of preformed pouches along a path of travel through the machine. The blower is positioned with respect to the path of travel, to inflate the preformed pouches. The sealing mechanism includes a heating element support and a heating element. The heating element support includes a sealing side and a belt preheating side. The heating element is disposed around at least a portion of the heating side and at least a portion of the belt preheating side. The drive includes a belt that is disposed around the heating element. The sealing mechanism is positioned with respect to the path of travel, to provide seals to the pouches to form inflated dunnage units. The heating element support is configured to maintain the heating element in contact with the heating element support preheating side.

RELATED APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 11/484,050 filed on Jul. 11, 2006 for APPARATUS AND METHOD FORMAKING FLUID FILLED UNITS, the entire disclosure of which is fullyincorporated herein by reference.

FIELD OF THE INVENTION

The present application relates to apparatus and methods for fillingfluid filled units.

BACKGROUND

Machines for forming and filling dunnage units from sheets of plasticare known. Machines which produce dunnage units by inflating preformedpouches in a preformed web are also known. For many applications,machines which utilize preformed webs are preferred.

SUMMARY

The present invention concerns a machine and a method for converting aweb of preformed pouches to dunnage units. In one exemplary embodimentthe machine includes a drive, a blower, and a sealing mechanism. Thedrive is arranged to move the web of preformed pouches along a path oftravel through the machine. The blower is positioned with respect to thepath of travel, to inflate the preformed pouches. The sealing mechanismincludes a heating element support and a heating element. The heatingelement support includes a sealing side and a belt preheating side. Theheating element is disposed around at least a portion of the heatingside and at least a portion of the belt preheating side. The driveincludes a belt that is disposed around the heating element. The sealingmechanism is positioned with respect to the path of travel, to provideseals to the pouches to form inflated dunnage units. The heating elementsupport is configured to maintain the heating element in contact withthe heating element support preheating side.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, which are incorporated in and constitute apart of this specification, embodiments of the invention areillustrated, which, together with a general description of the inventiongiven above, and the detailed description given below serve toillustrate the principles of this invention. The drawings and detaileddescription are not intended to and do not limit the scope of theinvention or the claims in any way. Instead, the drawings and detaileddescription only describe embodiments of the invention and otherembodiments of the invention not described are encompassed by theclaims.

FIG. 1 schematically illustrates a plan view of an exemplary machine inaccordance with the present invention for converting a web of preformedpouches to fluid filled units;

FIG. 2 schematically illustrates an elevational view of an exemplarymachine in accordance with the present invention for converting a web ofpreformed pouches to fluid filled units;

FIG. 2A schematically illustrates an elevational view of a secondembodiment of a machine in accordance with the present invention forconverting a web of preformed pouches to fluid filled units;

FIG. 2B schematically illustrates an elevational view of a thirdembodiment of a machine in accordance with the present invention forconverting a web of preformed pouches to fluid filled units;

FIG. 2C schematically illustrates an elevational view of a fourthembodiment of a machine in accordance with the present invention forconverting a web of preformed pouches to fluid filled units;

FIG. 3 illustrates a perspective view of an exemplary sealing mechanismin accordance with the present invention for sealing inflated pouches,in which a drive belt is shown in phantom lines;

FIG. 4 illustrates an elevational view of the exemplary sealingmechanism of FIG. 3;

FIG. 5 schematically illustrates an elevational view of an exemplaryheating element support and heating element in accordance with thepresent invention;

FIG. 6 schematically illustrates a bottom view of the heating elementsupport and heating element of FIG. 5; and

FIG. 7 schematically illustrates a top view of the heating elementsupport and heating element of FIG. 5.

DETAILED DESCRIPTION

The Detailed Description merely describes preferred embodiments of theinvention and is not intended to limit the scope of the claims in anyway. Indeed, the invention as described by the claims and thespecification is broader than and unlimited by the preferredembodiments, and the terms in the claims and specification have theirfull ordinary meaning.

The present invention concerns machines and methods of using suchmachines for converting a web of preformed pouches to dunnage units.Examples of webs of preformed pouches that can be converted to dunnageunits by machines in accordance with the present invention are shown anddescribed in U.S. patent application Ser. No. 11/141,304 to Wehrmann,filed May 31, 2005, and U.S. patent application Ser. No. 11/194,375 toWehrmann, filed Aug. 1, 2005, both of which are hereby incorporated intheir entirety. It should be readily apparent that other preformed webs,in addition to those disclosed in the above-referenced patentapplications, may be used in the machines disclosed herein to producedunnage units.

Referring to FIGS. 2 and 3, one embodiment of the present invention is amachine 10 for converting a web 12 of performed pouches to dunnageunits, with a heating element support 38 that maintains a heatingelement 40 in contact with a preheating side 54 of the heating elementsupport 38. In the example illustrated by FIG. 3, the preheating side 54is contoured to keep the heating element 40 in contact with the heatingelement support 38. The heating element 40 may be kept in contact withthe heating element support in a wide variety of other ways. Forexample, an automatic tensioning member, such as a spring or a manualtensioning member, such as a threaded fastener may press or pull theheating element 40 against the heating element support 38. The heatingelement 40 can be molded into the heating element support 38. Theheating element 40 can be glued to the heating element support. In theembodiment illustrated by FIG. 2A, a roller 100 presses the heatingelement 40 into contact with the preheating side 54 of the heatingelement support 38. The roller 100 may be biased into engagement withthe belt 46 with a spring or other biasing member as indicated by arrow102 or the position of the roller 100 may be fixed with respect to theheating element support 38 by a roller support 104. In the embodimentillustrated by FIG. 2B, a finger or extension member 106 presses theheating element 40 into contact with the preheating side 54 of theheating element support 38. The extension member 106 may be biased intoengagement with the belt 46 with a spring or other biasing member asindicated by arrow 108 or the position of the extension member 106 maybe fixed with respect to the heating element support 38 by a support110. In the embodiment illustrated by FIG. 2C, a brush 116 presses theheating element 40 into contact with the preheating side 54 of theheating element support 38. The brush 116 may be biased into engagementwith the belt 46 with a spring or other biasing member as indicated byarrow 118 or the position of the brush 116 may be fixed with respect tothe heating element support 38 by a support 118.

FIGS. 1 and 2 schematically illustrate an example of a machine 10 andprocess for converting webs 12 of preformed pouches to dunnage unitsthat may include a heating element support 38 that maintains the heatingelement 40 in contact with the heating element support. A heatingelement support 38 that maintains the heating element 40 in contact withthe heating element support can be implemented on a wide variety ofother machines for producing dunnage units from preformed webs. Anexemplary web 12 is routed from a supply 14 (shown in FIG. 2) to andaround a pair of elongated, transversely extending guide rollers 16. Theguide rollers 16 keep the web 12 taught as the web 12 is pulled throughthe machine 10. The web 12 includes a top elongated layer of plasticsuperimposed onto a bottom layer of plastic. Referring to FIG. 1, thelayers are connected along spaced edges, referred to as the inflationedge 18 and the opposite edge 20. In addition, a plurality oflongitudinally spaced, transverse seals 22 join the top and bottomlayers. Generally, each transverse seal 22 extends from the oppositeedge 20 to within a short distance of the inflation edge 18. Spacedpairs of lines of perforations 24 extend through the top and bottomlayers terminating a short distance from the edges 18 and 20. In oneembodiment, the web includes gap forming area 26 that extends betweeneach associated pair of lines of perforations 24. The gap forming area26 can serve to reduce stresses and other unwanted forces on the poucheswhile the pouches are inflated. In other embodiments, the gap formingarea 26 is not included. For example uniform perforations 24 may extendfrom one side of the web to the other side of the web in a uniformmanner.

Referring again to FIGS. 1 and 2, at location A of the machine 10, theweb of pouches are uninflated. As the web 12 moves through the machine10, along a path of travel T, a longitudinally extending guide pin 28 isdisposed in the web 12 at station B. The guide pin 28 is disposed in apocket bounded by the top and bottom layers of plastic, the inflationedge 18, and the ends 29 of the transverse seals 22, located proximateto the inflation edge 18. The guide pin 28 aligns the web 12 as the web12 is pulled along the path of travel T through the machine 10. A cutter30 extends from the guide pin 28 and is used to cut the inflation edge18 of the web 12. The cutter 30 slits the inflation edge 18 as the web12 moves through the machine 10 to provide inflation openings 32 (SeeFIG. 2) into the pouches.

A blower 34 is positioned after the cutter 30 at station B of themachine 10 and inflates the preformed pouches as the web 12 moves pastthe blower 34. A sealing mechanism or assembly 36 is positioned atstation C of the machine 10 to form a seal to close the pouches andcomplete the dunnage units. In the illustrated embodiment, the sealingassembly 36 includes a pair of heating element supports 38, a pair ofheating elements 40, a pair of cooling elements 42. A drive 48 includesa pair of drive rollers 44 that are driven by one or more motors 45, anda pair of drive belts 46 (shown in FIG. 2) that are driven by therollers 44. The drive 48 moves the web 12 along the path of travel Tthrough the machine 10. The illustrated drive 48 can be replaced by anydrive that can move the web along the path of travel. In an alternateembodiment, the pair of cooling elements 42 are omitted.

As best seen in FIGS. 3 and 4, an example of a suitable heating elementsupport 38 is a block formed or fabricated from an insulating materialand structurally capable of supporting a heating element 40. Examples ofsuitable materials for the heating element support include Teflon,ceramics, plastic materials and a wide variety of other materials. Anexample of a suitable heating elements 40 is a heating wire made of anelectrically conductive material. Resistance in such a wire causes theheating wire to heat up when a voltage is applied to the wire. Theillustrated drive 48 may be replaced by any drive that can move the webalong the path of travel.

In the exemplary embodiment, each heating element is disposed around oneof the heating element supports The heating elements are secured totheir heating element supports 38 by attachment members 50. In theembodiment illustrated by FIGS. 3 and 4, attachment members 50 areposts. However, the attachment members 50 may be any mechanism formechanically attaching the heating elements to the insulation blocksthat allows a voltage to be applied to the heating element. The heatingelements 40 are secured to the posts 50 such that the machine 10 canselectively apply voltage to the wires 40 to heat the wires 40. Thevoltage is applied to the wires 40 such that the wires 40 reach agenerally consistent operating temperature that is effective in sealingan inflated pouch to form a dunnage unit.

In the illustrated embodiment, each drive belt 46 is a loop of materialthat is disposed around its respective drive roller 44, insulation block38, and cooling element 42, if included. The drive belts can be madefrom a wide variety of different materials. For example, the drive beltscan be made from Teflon impregnated fiberglass cloth. As best seen inFIG. 4, the drive belt 46 is also disposed around the heating element 40such that the heating element is 40 positioned between the drive belt 46and the heating element support 38.

The drive belts 46 are driven by the drive rollers 44 and moves along agenerally oval path about the heating element support 38, coolingelement 42, and drive roller 44. As best seen in FIGS. 2 and 3, the pairof drive belts 46 contact and engage one another along the path oftravel T of the web 12 through the machine 10. This contact andengagement causes the drive belts 46 to grasp the web 12 and pull theweb 12 through the machine 10, first past the heating wires 40 and then,optionally, past the cooling elements 42.

A seal is formed between the top layer and bottom layer of each pouchwhen the layers are exposed to heat from the heating element 40. Theseal is positioned to intersect with the transverse seals 22. This heat,applied to the top and bottom layers of plastic, causes the plastic tobecome molten and flow, such that portions of the plastic proximate tothe heat source merged. As this area cools, a sealed area is formed toclose a pouch. The cooling process can be accelerated by the extractionof heat from the sealed area of the pouch. This accelerated cooling canbe accomplished by moving the web 12 to position the sealed areaproximate to the cooling element 42. The cooling element 42 may beformed or fabricated from any suitable heatsink material, whichtransfers heat away from the sealed area. One example of such a materialis aluminum.

Quality and consistency of seals is ensured by ensuring that thetemperature of the heating element 40 is maintained at an intendedsealing temperature. For example, the temperature of a wire heatingelement may be maintained at between 200-400 degrees Fahrenheit. Thetemperature of a heating element 40 is a function of the voltage appliedto the heating element 40 and the environment the heating element 40operates in (i.e., the medium that dissipates heat from the wire). Thevoltage applied to the heating element 40 determines how much heat isgenerated by the heating element 40 and the environment the heatingelement 40 is operated in determines how rapidly heat dissipates fromthe heating element 40. If the operating conditions vary along thelength of the heating element 40, then the temperature of the heatingelement 40 may differ at discrete locations along the length of theheating element 40. This disparity in temperatures along the heatingelement 40 can cause one section or portion of heating element 40 toincrease in temperature. For example, if one portion of the wire doesnot contact the heating element support 38, that portion may becomesignificantly hotter than other portions of the wire.

Each heating element support 38, which is an insulation block in theillustrated embodiment has a sealing side 52 and a belt preheating side54. The sealing side 52 of the heating element support 38 is along thepath of travel T, where the drive belts 46 are in contact with oneanother. The belt preheating side 54 is on the opposite side of theheating element support 38. The belt preheating side 54 serves to heatthe drive belts 46 as the belt 46 passes to preheat the belt and enhancethe transfer heat through the belt 46 to the pouches that are sealedalong the sealing side 52 of the heating element support 38.

The portion of the heating element 40 along the sealing side 52 isclamped between each pair of heating element supports 38 to ensure thatthe pair of drive belts 46 are in contact and engaged. This clampingkeeps the portion of heating element 40 along the sealing side 52 incontact with both the heating element support 38 and the drive belt 46.On the belt preheating side 54, there is no clamping force to ensurethat the heating element 40 stays in contact with both the drive belt 46and the heating element support 38 in the illustrated embodiment.Because the heating element support dissipates heat, if the heatingelement 40 is not in contact with the heating element support 38, thetemperature along that portion of wire 40 will differ from thetemperature of the portion of heating element disposed 40 along thesealing side 52. For example, the heating element on the preheating sidecould become too hot and/or make the belt too hot.

The shape and contour of the belt preheating side 54 may be designedsuch that the portion of the heating element 40 along the beltpreheating side 54 of the heating element support 38 stays in contactwith the heating element support 38. In one embodiment, the shape of theheating element support also causes the heating element 38 to stay incontact with the belt 46. As is shown in FIGS. 3, 4, and 5, the beltpreheating side 54 of the heating element support 38 can be fabricatedto be generally curved, convex, or arcuate. As best seen in FIG. 4, aconvex, generally curved shape maintains the heating element 40 incontact with the belt 46 and the heating element support 38 along theentire belt preheating side 54.

Although the heating element has been shown and described as a heatingwire disposed along the sealing and belt preheating sides of aninsulation block, it should be understood that a heating element inaccordance with the present invention can take an a variety ofembodiments and be disposed in a variety of arrangements. For example, aheating element may be a band of material or a plurality of discretelydispersed material. In addition, a heating element may be disposed onlyaround a portion of the sealing side or the a portion of the beltpreheating side. The heating element support is illustrated as aninsulation block is having a curved, convex, or arcuate belt preheatingside. The heating element support may be made from any material and maybe in any shape and/or configuration that supports a heating elementsuch that the heating element does not overheat.

While various aspects of the invention are described and illustratedherein as embodied in combination in the exemplary embodiments, thesevarious aspects may be realized in many alternative embodiments notshown, either individually or in various combinations andsub-combinations thereof. Unless expressly excluded herein all suchcombinations and sub-combinations are intended to be within the scope ofthe present invention. Still further, while various alternativeembodiments as to the various aspects and features of the invention,such as alternative materials, structures, configurations, methods,devices, and so on may be described herein, such descriptions are notintended to be a complete or exhaustive list of available alternativeembodiments, whether presently known or later developed. Those skilledin the art may readily adopt one or more of the aspects, concepts orfeatures of the invention into additional embodiments within the scopeof the present invention even if such embodiments are not expresslydisclosed herein. Additionally, even though some features, concepts oraspects of the invention may be described herein as being a preferredarrangement or method, such description is not intended to suggest thatsuch feature is required or necessary unless expressly so stated. Stillfurther, exemplary or representative values and ranges may be includedto assist in understanding the present invention however; such valuesand ranges are not to be construed in a limiting sense and are intendedto be critical values or ranges only if so expressly stated.

1) A machine for converting a web of preformed pouches to dunnage units,the machine comprising: a drive including at least one motor and atleast one belt for moving the web along a path of travel; a blowerpositioned with respect to the path of travel for inflating thepreformed pouches; and a sealing mechanism positioned with respect tothe path of travel to provide seals to the pouches to form inflateddunnage units, the sealing mechanism comprising: a heating elementsupport having a sealing side and a belt preheating side; a heatingelement disposed around at least a portion of the sealing side anddisposed around at least a portion of the belt preheating side; the beltis disposed around the heating element and driven by the motor; whereinthe heating element support is shaped to maintain the heating element incontact with the heating element support preheating side. 2) The machineof claim 1 wherein the belt preheating side is contoured to maintain theheating element in contact with the belt preheating side. 3) The machineof claim 2 wherein the belt preheating side comprises a convex surface.4) The machine of claim 2 wherein the belt preheating side comprises acurved surface. 5) The machine of claim 2 wherein the belt preheatingside comprises an arcuate surface. 6) The machine of claim 2 whereinsubstantially an entire length of the belt preheating side is convex. 7)The machine of claim 2 wherein substantially an entire length of thebelt preheating side is curved. 8) The machine of claim 2 whereinsubstantially an entire length of the belt preheating side is arcuate.9) The machine of claim 1 wherein the heating element support is madefrom an insulating material. 10) The machine of claim 1 furthercomprising a second sealing mechanism and wherein the web is clampedbetween the two sealing mechanisms. 11) The machine of claim 1 whereinthe pouches are defined by transverse seals that extend from a remoteedge to within a predetermined distance of an inflation edge. 12) Themachine of claim 11 wherein the seal is longitudinal with respect to thepath of travel and intersects the transverse seals to close thepreformed pouches. 13) The machine of claim 1 further comprising acooling element positioned to cool the seal formed by the sealingmechanism. 14) The machine of claim 13 wherein the cooling element is aheat dissipating block that transfers heat away from the seal. 15) Amethod for converting a web of preformed pouches to dunnage units, themethod comprising: moving the web along a path of travel; inflating thepreformed pouches; preheating a portion of a seal belt with a heatingelement on a preheating side of a heating element support; maintainingthe heating element in contact with the preheating side; moving thepreheated belt to a seal side of the heating element support; engagingthe web on the seal side of the heating element support with the belt;and providing seals to the pouches at the seal side of the heatingelement support to form inflated dunnage units. 16) The method of claim15 wherein the heating element is maintained in contact with thepreheating side by providing the preheating side with a convex surface.17) The method of claim 15 wherein the heating element is maintained incontact with the preheating side by providing the preheating side with acurved surface. 18) The method of claim 15 wherein the heating elementis maintained in contact with the preheating side by providing thepreheating side with an arcuate surface. 19) The method of claim 15wherein substantially an entire length of the preheating side is incontact with the heating element. 20) The method of claim 15 furthercomprising engaging the formed seal with a cooling element to cool theformed seal.